/Engine/Source/Runtime/Engine/Classes/Kismet/KismetMathLibrary.h
Returns a desaturated color, with 0 meaning no desaturation and 1 == full desaturation
Desaturated color
static [FLinearColor](API\Runtime\Core\Math\FLinearColor) LinearColor_Desaturated ( [FLinearColor](API\Runtime\Core\Math\FLinearColor) InColor, float InDesaturation )